ASTM D4065_2001

graphical representation of elasticity and damping as a function of temperature or frequency.
5.2This procedure can be used to locate transition tempera-tures of plastics,that is,changes in the molecular motions of a polymer.In the temperature ranges where significant changes occur,elastic modulus decreases rapidly with increasing tem-perature(at constant or near constant frequency)or increases with increasing frequency(at constant temperature).A maxi-mum is observed for the loss modulus.
5.3This procedure can be used,for example,to evaluate by comparison to known reference materials:
5.3.1Degree of phase separation in multicomponent sys-tems,
5.3.2Filler type,amount,pretreatment,and dispersion,and 5.3.3Effects of certain processing treatment.
5.4This procedure can be used to determine the following: 5.4.1Stiffness of polymer composites,especially as a func-tion of temperature,
5.4.2Degree of polymer crystallinity,and
5.4.3Magnitude of triaxial stress state in the rubber phase of rubber modified polymers.
5.4.4This procedure is useful for quality control,specifica-tion acceptance,and research.
5.5For many materials,there may be a specification that requires the use of this practice,but with some procedural modifications that take precedence when adhering to the specification.Therefore,it is advisable to refer to that material specification before using this practice.Table1of Classifica-tion System D4000lists the ASTM materials standards that currently exist.
6.Interferences
6.1Since small quantities of specimen are used,it is essential that the specimens be homogeneous or representative, or both.
7.Apparatus
7.1The function of the apparatus is to hold a plastic specimen of uniform cross section,so that the specimen acts as the elastic and dissipative element in a mechanically oscillated system.Instruments of this type are commonly called dynamic mechanical or dynamic thermomechanical analyzers.They typically operate in one of seven oscillatory modes:(1)freely decaying torsional oscillation,(2)forced constant amplitude, resonant,flexural oscillation,(3)forced constant amplitude,fixed frequency,compressive oscillation,(4)forced constant amplitude,fixed frequency,flexural oscillation,(5)forced, constant amplitude,fixed frequency,tensile oscillation,(6) forced constant amplitude,fixed frequency,torsional oscilla-tion and(7)forced constant amplitude,fixed frequency,or variable frequency dual cantilever.
7.2The apparatus shall consist of the following:
7.2.1Clamps—A clamping arrangement that permits grip-ping of the sample.
7.2.2Oscillatory Deformation(Strain)—A device for ap-plying an oscillatory deformation(strain)to the specimen.The deformation(strain)may be applied and then released,as in free-vibration devices,or continuously applied,as in forced-vibration devices(see Table1).
7.2.3Detectors—A device or devices for determining de-pendent and independent experimental parameters,such as force(stress or strain),frequency,and temperature.Tempera-ture should be measureable with an accuracy of61°C, frequency to61%,and force to61%.
7.2.4Temperature Controller and Oven—A device for con-trolling the specimen temperature,either by heating(in steps or ramps),cooling(in steps or ramps),or maintaining a constant specimen environment.Any temperature programmer should be sufficiently stable to permit measurement of sample tem-perature to60.5°C.
7.3Nitrogen or other gas supply for purging purposes. 7.4Calipers or other length-measuring device capable of measuring to an accuracy of0.01mm.
8.Hazards
8.1Precautions:
8.1.1Toxic or corrosive effluents,or both,may be released when heating the specimen near its decomposition point and can be harmful to personnel or to the apparatus.
8.1.2Take care to prevent buckling of the clamped speci-men due to thermal expansion during the test.
9.Test Specimens
9.1Specimens may be any uniform size or shape but are ordinarily analyzed in rectangular form.If some heat treatment is applied to the specimen to obtain this preferred analytical form,this treatment should be noted in the report.
9.2Due to the numerous
types of dynamic mechanical instruments,specimen size is notfixed by this practice.In many cases,a specimen of0.75by9.4by50mm(0.03by0.38 by2.0in.)is found to be usable and convenient.
N OTE3—It is important to select a specimen size consistent with the modulus of the material under test and capabilities of the measuring apparatus.For example,thick specimens of low modulus materials may be suitable for measurement,while thin specimens of high modulus materials may be required.
9.3Condition the specimen at2362°C(7364°F)and50 65%relative humidity for not less than40h prior to test in accordance to Procedure A of Practice D618,for those tests where conditioning is required.If other specimen conditioning is used,it should be noted in the report.
10.Calibration
10.1Using the same heating rate or schedule to be used for specimens,calibrate the instrument temperature axis,using the instrument manufacturer’s procedures with either or both of the following substances.
Standard Transition Temperature,°C Type of Transition
Water0.0fusion
Indium156.6fusion
10.2Calibrate the instrument using procedures recom-mended by the manufacturer.
11.Procedure
11.1Measure the length,width,and thickness of the speci-men to an accuracy of61%.
11.2Maximum strain amplitude should be within the linear viscoelastic range of the material.Strains of less than1%are recommended.
11.3If temperature is to be the independent variable:
11.3.1The test frequency may be from0.01to500Hz,fixed
or changing as the dependent variable.
TABLE1Summary of Techniques and Calculations Used to Determine Dynamic Mechanical Properties
Sinusoidal fixed frequency Forced constant fixed frequency-tensile oscillation (see Fig.4)
Sinusoidal fixed or Forced constant amplitude;
fixed or variable
0.0016
variable frequency
frequency-tensile oscillation(see Fig.5) Forced constant amplitude;fixed or variable frequency-compressive oscillation(see Fig.6)
Forced constant amplitude;fixed or variable frequency-flexural oscillation(see Fig.7)
Technique
Input
Excitation
Mode of Oscillation
Frequency Range,
Hz
Specimen Size,
mm
Calculations
Oscillating
Strain
Elastic
Component
Damping
Component
r=0.25–3.2
L=63.5
3ra/L2Circular cross
section:
E8=4NL3
cos d/3r4a
E9=4NL3sin d/
3r4a
Tan d directly read
Dynamic Mechanical Sinusoidal
fixed or
Constant force
amplitude;
0.01–50t=up to2.0
b=up to10
D L/L Rectangular cross
section:
Analyzer B,D variable
frequency fixed or variable
frequency-tensile
L=up to24E8=NL cos d/bt
D/L
E9=NL sin d/
tb D L
oscillation(see Fig.5)Tan d directly
read
r=up to2.0
L=up to24
D L/L Circular cross
section:
E8=NL cos d/p r2
D/L
E9=NL sin d/p r2
D/L
Tan d directly read
Dynamic Sinusoidal Constant force amplitude;0.01–50Up to3320D L/L Rectangular cross
Mechanicalfixed orfixed or variable t=up to20section:
Analyzer B,D variable frequency-compression b=up to20E8=NL cos d/tb E9=NL sin d/ frequency oscillation(see Fig.6)L=0.001-24D L tb D L
r=1–20Tan d directly
read
t=up to20
D L/L Circular cross
section:
E8=NL cos d/p r2 D L E9=NL cos d/
p r2D L
Tan d directly read
Dynamic Mechanical Analyzer B,D Sinusoidal
fixed or
variable
frequency
Constant force amplitude;
fixed or variable
frequency-flexural
oscillation(see Fig.7)
0.01–50t=up to24
b=up to10
L=up to20
3ta/L2
E8
2
r=up to5
L=up to20
3ra/L2
E8
Mechanical spectrometer B,C Sinusoidal
fixed or
variable
frequency
Forced constant amplitude;
fixed or variable
frequency-torsional
oscillation(see Fig.8)
0.0016–800.5to6.4t12.7b
63.5L
Rectangular
cross
section:
K u
(3a+1.8b)/
8b2L t2
G8
K
Tan d directly read
3.2,
4.7,6.4dia,
63.5L
Circular
cross
section:
Circular cross
section:
Technique
Input
Excitation
Mode of Oscillation
Frequency Range,
Hz
Specimen Size,
mm
Calculations
Oscillating
Strain
Elastic
Component
Damping
Component
r u/L G8=2TL cos d/p r4u G9=2TL sin d/p r4u
Tan d directly read
Mechanical spectrometer B,C Sinusoidal
fixed
frequency
Forced constant amplitude
fixed frequencyflexural
oscillation(single or dual
cantilever)
.01–200L=1–46
t=.1–5
b=.1–18
3ta/L2
E85
S810D
2b~t/L!3
Tan d directly read
Mechanical spectrometer B,C Sinusoidal
fixed
frequency
Forced constant amplitude
fixed frequency shear
oscillation
.01–200t=.1–3a/t
G85
S810D t
2A
Tan d directly read
Mechanical spectrometer B,C Sinusoidal
fixed
frequency
Forced constant amplitude
fixed frequency tensile
oscillation
.01–100t=.005–1
b=.01–18
L=1–20
a/L
E85
S810D L
wt
Tan d directly read
available from IMASS,Inc.,Box
available from TA Instruments,
available from Rheometric-Scientific,
available from The Perkin-Elmer
inertial member
clamp
D L=change in length n=number of cycles for oscillation to decay a specific amount E8=elastic modulus P=period of oscillation
E9=loss modulus d=phase angle
N=axial force
Z=elapsed time
R=instrument arm length
11.3.2Vary the temperature of the test specimen from the lowest to the highest temperature of interest while measuring its elastic and viscous properties.
N OTE4—Preferably,tests conducted over a temperature range should be performed in incremental steps or at a rate slow enough to allow temperature equilibrium throughout the entire specimen.The time to reach equilibrium will depend upon the mass of the particular specimen and the gripping arrangement.Temperature program rates of1to2°C/min or2to 5°C step intervals held for3to5min have been found suitable.The effect of heating rate may be observed by running specimens at two or more rates and comparing the elastic and viscous property results obtained.
N OTE5—The accuracy required of the temperature measurement will depend upon the rate of change of moduli with temperature of the plastic being investigated.In transition regions,experience has indicated that the specimen temperature should be read to60.5°C.
11.3.3Duplicate specimens should be examined,and the mean results reported.
11.4If frequency is to be the independent variable:
11.4.1The test temperature should befixed at the desired value.
11.4.2Vary the frequency applied to the test specimen while measuring its elastic and viscous properties.
11.4.3Duplicate specimens should be examined and the mean results reported.
12.Calculation
12.1Calculate the dynamic mechanical properties using the equations given in Table1or in the manufacturer’s operating manual.
12.1.1Use the average measured values of specimen length, width,and thickness.
13.Report
13.1Report the following information:
13.1.1Complete identification and description of the mate-rial tested including name,stock or code number,date made, form,source,etc.
13.1.2Description of the instrument used for test.
13.1.3Dimensions of the test specimen.
13.1.4Description of the calibration procedure.
13.1.5Identification of the sample atmosphere by gas com-position,purity,and rate used.
13.1.6Details of conditioning the specimen prior to test.
13.1.7The temperature program including initial andfinal temperatures as well as rate of linear temperature change or size and duration of temperature steps.
13.1.8Table of data and results.
13.1.9Number of specimens tested.
13.1.10A plot of the elastic moduli and loss moduli versus temperature(or frequency)where tests are conducted at more than one temperature(or frequency).
13.1.10.1Moduli should be plotted on the ordinate with upward deflections as increase in elasticity and damping.The ordinate should be clearly labeled with title and units of measurement.
13.1.10.2Temperature,frequency,or time should be plotted on the abscissa,increasing from left to right.The abscissa should be clearly labeled with title and units of measurement.
13.1.10.3Transition temperatures are taken from the peak values in the loss modulus profile.
13.1.10.4Wherever possible,each thermal effect should be identified and supplementary supporting evidence reported.
13.1.11Average values and standard deviations of elastic (or relative rigidity)and loss modulus(or damping)reported to two significantfigures.
13.1.12Date of test.
13.1.13Maximum strain
amplitude and frequency.
13.1.14Equations used to calculate values.
14.Keywords
14.1dynamic mechanical;modulus;rheological;tan delta;
viscoelastic
SUMMARY OF CHANGES
This section identifies the location of selected changes to this practice.For the convenience of the user, Committee D20has highlighted those changes that may impact the use of this practice.This section may also include descriptions of the changes or reasons for the changes,or both.
D4065–01:
(1)Title has been changed.
(2)ISO statement has been added.(3)Footnote C in Table1has been pany name change.
(4)Summary of Changes section added.
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